New API SN oil spec?

Ecomike

Ecomike

NAXJA# 2091
Location
MilkyWay Galaxy
I was foraging for the old SL oil spec oil at Advance auto this week, and found their name brand oil listed SN, not SM on the API logo spec. Is this a miss print, or did an SN spec come out while I was snoozing? I am guessing it would have NO ZINC or phosphate in it?

So did I miss something?

I am having a real hard time finding any diesel oil anywhere now that does not have the SM API spec on the label, and the Autozone SL spec, 20W-50 is getting hard to find to. I am may getting close to the point where I need to rethink what oil and spec, and possibly additive I use.
 
I use Valvoline VR racing oil in both my 70 Charger and 89 Cherokee. Cost is some bit higher but rated as "off road" it still has a good mix.
 
http://www.rmmengines.com/Joe_Gibbs_Oil.html

They have 7000 PPM of ZDP in their oils!!!!!

http://www.g503.com/advertising/oil-spec.pdf

Interesting that they are finally admitting that the new viscosity modifiers in newer oils, break down under stress in older engines, leading to oil pressure drops!!! Something I have been convinced of for years now!

API SN – ILSAC GF-5 licensed oil will hit the shelves in October of 2010, and this new oil
specification places greater emphasis on protecting catalytic converters than previous oil
standards. While this is good news for emissions, improved catalytic converter life has proven
to be detrimental to flat-tappet camshaft life.
Both the new API SN and GM dexos oil standards will require the use of a new type of
“Phosphorus Retention” ZDP. ZDP or Zinc, as it is known, provides protection for engine
components by creating a phosphate film. The creation of this phosphate film also results in a
reduction of performance in Three Way Catalytic Converters. The new “Phosphorus Retention”
ZDP is less reactive, so it is less detrimental to catalytic converter performance. It is unknown
how this new “Phosphorus Retention” ZDP will perform in flat-tappet and high performance
engines.
Another change associated with API SN/ILSAC GF-5 oils will be greater fuel economy
performance. This improvement in fuel economy will be achieved by increased use of
polymers called Viscosity Modifiers. These polymers help a “thin” oil act “thicker” under low
stress conditions. While the liberal use of polymers helps improve fuel economy in modern
passenger car engines, older style push-rod and race engines produce greater shear stresses
that can “tear” these polymers. When these polymers are sheared, oil losses viscosity, and that
can lead to increased wear.
Click to expand...
 
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I've seen the recycled oil local..
You can add zddp additive to oil. But I would think that diesel needs it just like our XJ's
I work for a GM dealer. I should send some of the Dexos in for oil analysis.

Ecomike, why not just use Amsoil?
Do you have a Costco nearby? I have seen diesel oil at my local warehouse, The Chevron Rotella and Delo
 
Johnnie Walker said:
I've seen the recycled oil local..
You can add zddp additive to oil. But I would think that diesel needs it just like our XJ's
I work for a GM dealer. I should send some of the Dexos in for oil analysis.

Ecomike, why not just use Amsoil?
Do you have a Costco nearby? I have seen diesel oil at my local warehouse, The Chevron Rotella and Delo
Click to expand...

That's why the API SM oil didn't carry a Cx rating - the highest "two-way" oil before was API SL/CJ-4.

It's all well and good that newer engines tolerate the newer oils without trouble, but it's almost as bad as Microsoft - once they come out with something new, they don't want to support the earlier versions that worked quite well, thank you very much (I've been dragged kicking and screaming into WinXP and Win7 - I'd have been perfectly happy to stick with Win2K Pro and leave it at that! 2K is what NT was supposed to be, and is probably the best version of Windows I've run across...)

Gear oil specs (GL-x) ratings aren't reverse-compatible, which is why well-stocked parts houses will carry GL-3, GL-5, and performance synthetic gear oils. But, API SM gets carried, SL gets dropped, and you have to spend extra money to get the antiscuff additive (which I'd figure was intentional on part of the refiners, but I don't think they make the ZDDP additives.)

Race oil makers have got to be making a killing, tho. Most of the flat tappet engines still on the road belong to enthusiasts who don't want to get quit of them - most imports made in the last 12-15 years have roller followers, and many domestics are running roller tappets or roller OHC followers as well (and therefore can survive just fine without the ZDDP.) Also, "Big 3" engines can usually be converted to run roller tappets - so they can be converted to survive the newer oils as well. We're stuck.
 
Johnnie Walker said:
I've seen the recycled oil local..
You can add zddp additive to oil. But I would think that diesel needs it just like our XJ's
I work for a GM dealer. I should send some of the Dexos in for oil analysis.

Ecomike, why not just use Amsoil?
Do you have a Costco nearby? I have seen diesel oil at my local warehouse, The Chevron Rotella and Delo
Click to expand...

My diesel is a 1981-82 Nissan SD-22, with unknown miles on it. I dare not risk synthetic on it, and the synthetics are even more of an unknown for an engine this old. IK tried synthetic on my 87 Jeep, and that was a disaster!

The local stores have diesel oil, but they are all stocking only the latest EPA/API oil spec on them for the new diesel engines, CJ-4/SM spec which has far less zinc, less phosphate and less sulfur than the CI or CH spec did, or even the CJ-4/SL. I found some CH-4/SL, Warren Petroleum Diesel oil about 2 years ago, that I stocked up on, but I have not been able to find it in Houston for the last 6-8 months, and I am out, and need to change the oil badly.

While I can add ZDDP (which has zinc, phosphate and organic sulfur), it does not add the other detergents, and ash (?, which has to do with its capacity to neutralize acids as they form IIRC) handling properties compounds that were in the older diesel oil specs.

From Wiki: "In addition to the viscosity index improvers, motor oil manufacturers often include other additives such as detergents and dispersants to help keep the engine clean by minimizing sludge buildup, corrosion inhibitors, and alkaline additives to neutralize acidic oxidation products of the oil. Most commercial oils have a minimal amount of zinc dialkyldithiophosphate as an anti-wear additive to protect contacting metal surfaces with zinc and other compounds in case of metal to metal contact. The quantity of zinc dialkyldithiophosphate is limited to minimize adverse effect on catalytic converters. Another aspect for after-treatment devices is the deposition of oil ash, which increases the exhaust back pressure and reduces over time the fuel economy. The so-called "chemical box" limits today the concentrations of sulfur, ash and phosphorus (SAP)."
 
After looking through Wally world, I found SL rated oil on the shelf.... it was Mobil-1 High milage full synthetic. I was wary of starting my 200000 plus mile engine on synthetic, but after having it in there for several months now, I have had no issues. They had it in 5w30 and 10w40.
 
I do not dare put a synthetic or semi-synthetic in my 30 year old diesel. I am still looking for a CH-4/SL (highest rating) 15W40 or 20W50 diesel, dyno oil.
 
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